// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/public/test/test_browser_thread_bundle.h"

#include "base/logging.h"
#include "base/memory/ptr_util.h"
#include "base/message_loop/message_loop.h"
#include "base/run_loop.h"
#include "base/test/scoped_async_task_scheduler.h"
#include "base/test/scoped_task_scheduler.h"
#include "content/browser/browser_thread_impl.h"
#include "content/public/test/test_browser_thread.h"

namespace content {

TestBrowserThreadBundle::TestBrowserThreadBundle()
    : TestBrowserThreadBundle(DEFAULT)
{
}

TestBrowserThreadBundle::TestBrowserThreadBundle(int options)
    : options_(options)
    , threads_created_(false)
{
    Init();
}

TestBrowserThreadBundle::~TestBrowserThreadBundle()
{
    DCHECK(threads_created_);

    // To avoid memory leaks, we must ensure that any tasks posted to the blocking
    // pool via PostTaskAndReply are able to reply back to the originating thread.
    // Thus we must flush the blocking pool while the browser threads still exist.
    base::RunLoop().RunUntilIdle();
    BrowserThreadImpl::FlushThreadPoolHelperForTesting();

    // To ensure a clean teardown, each thread's message loop must be flushed
    // just before the thread is destroyed. But stopping a fake thread does not
    // automatically flush the message loop, so we have to do it manually.
    // See http://crbug.com/247525 for discussion.
    base::RunLoop().RunUntilIdle();
    io_thread_->Stop();
    base::RunLoop().RunUntilIdle();
    cache_thread_->Stop();
    base::RunLoop().RunUntilIdle();
    process_launcher_thread_->Stop();
    base::RunLoop().RunUntilIdle();
    file_user_blocking_thread_->Stop();
    base::RunLoop().RunUntilIdle();
    file_thread_->Stop();
    base::RunLoop().RunUntilIdle();
    db_thread_->Stop();
    base::RunLoop().RunUntilIdle();
    // This is the point at which we normally shut down the thread pool. So flush
    // it again in case any shutdown tasks have been posted to the pool from the
    // threads above.
    BrowserThreadImpl::FlushThreadPoolHelperForTesting();
    base::RunLoop().RunUntilIdle();
    ui_thread_->Stop();
    base::RunLoop().RunUntilIdle();

    scoped_async_task_scheduler_.reset();
    scoped_task_scheduler_.reset();

    // |message_loop_| needs to explicitly go away before fake threads in order
    // for DestructionObservers hooked to |message_loop_| to be able to invoke
    // BrowserThread::CurrentlyOn() -- ref. ~TestBrowserThread().
    CHECK(message_loop_->IsIdleForTesting());
    message_loop_.reset();
}

void TestBrowserThreadBundle::Init()
{
    // Check for conflicting options can't have two IO threads.
    CHECK(!(options_ & IO_MAINLOOP) || !(options_ & REAL_IO_THREAD));
    // There must be a thread to start to use DONT_CREATE_THREADS
    CHECK((options_ & ~IO_MAINLOOP) != DONT_CREATE_THREADS);

    // Create the UI thread. In production, this work is done in
    // BrowserMainLoop::MainMessageLoopStart().
    if (options_ & IO_MAINLOOP) {
        message_loop_.reset(new base::MessageLoopForIO());
    } else {
        message_loop_.reset(new base::MessageLoopForUI());
    }

    ui_thread_.reset(
        new TestBrowserThread(BrowserThread::UI, message_loop_.get()));

    if (!(options_ & DONT_CREATE_THREADS))
        CreateThreads();
}

// This method mimics the work done in BrowserMainLoop::CreateThreads().
void TestBrowserThreadBundle::CreateThreads()
{
    DCHECK(!threads_created_);

    if (options_ & REAL_TASK_SCHEDULER) {
        scoped_async_task_scheduler_ = base::MakeUnique<base::test::ScopedAsyncTaskScheduler>();
    } else {
        scoped_task_scheduler_ = base::MakeUnique<base::test::ScopedTaskScheduler>(message_loop_.get());
    }

    if (options_ & REAL_DB_THREAD) {
        db_thread_.reset(new TestBrowserThread(BrowserThread::DB));
        db_thread_->Start();
    } else {
        db_thread_.reset(
            new TestBrowserThread(BrowserThread::DB, message_loop_.get()));
    }

    if (options_ & REAL_FILE_THREAD) {
        file_thread_.reset(new TestBrowserThread(BrowserThread::FILE));
        file_thread_->Start();
    } else {
        file_thread_.reset(
            new TestBrowserThread(BrowserThread::FILE, message_loop_.get()));
    }

    file_user_blocking_thread_.reset(new TestBrowserThread(
        BrowserThread::FILE_USER_BLOCKING, message_loop_.get()));
    process_launcher_thread_.reset(new TestBrowserThread(
        BrowserThread::PROCESS_LAUNCHER, message_loop_.get()));
    cache_thread_.reset(
        new TestBrowserThread(BrowserThread::CACHE, message_loop_.get()));

    if (options_ & REAL_IO_THREAD) {
        io_thread_.reset(new TestBrowserThread(BrowserThread::IO));
        io_thread_->StartIOThread();
    } else {
        io_thread_.reset(
            new TestBrowserThread(BrowserThread::IO, message_loop_.get()));
    }

    threads_created_ = true;
}

} // namespace content
